Improvement in speaking-telephones



W. GILLETT. Speaking-Telephone,

No.,213,283 Patented Mar.18, 1879.

UNITED STATES PATENT OEEIoE.

VEBSTER GLLETT, OF YFSILANTI, MIGHGAN.

IMPROVEMENT IN SPEAKING-TELEPHONES.

Specilcation forming part or' Letters Patent No. 213,283, dated March 18, 1879; application tiled November 27, 1878.

To all @thorn t may concern:

Be it known that i, WEnsTEn GILLETT, of Ypsilanti, in the county otWashtenaw, Michigan, have invented an improvement in Speaking-Telephones or Acoustic Telegraphs; and do hereby declare the ioliowing to be a full and c ,rrect description.

1n the accompanying drawings, Figure 1 is a side view oi' a telegraph-operators table to which is attached my improvement in telephones, the same showing also an inductioncoil, ali arranged with a series of posts better to illustrate my improvements in connection with a telegraph. Fig. 2 is a section showing the arrangement ot' my apparatus detached from the induction-coil andtable, Fig. 1. Fig. i is a section of myimproved mouth-piece and its connection with a speaking-tube.

My invention relates to an acoustic telegraph apparatus or speaking microphones; and my invention consists, first, in a diaphragm provided with a pin with its point in contact with powdered carbon, (or other poor conductor et' electric iniinence,) in combination with a disk of rubber and speaking-tube or acoustic instrument and an induction-coil.

L1 'the accompanying drawings, Fig. 1 is a side view et' a telegraplr-operatons table, A, with the usual series et bindingposts B C i), etc., and a receiving-magnet, H, all ofwhich require no further description. Below the table rk is seen the case I, which contains my improvement. as is better shown in section, Figs. 2 and .1). Across the mouth ot the case i is placed a metallic diaphragm, K, having one of the wires connecting therewith, while the other wire is connected with the collar X as seen in Fig. L.

Lhe pin L ot' the diaphragm has a small disk ot' metal hearing on a piece of india-rubber, while trie platinum point et' the pin is in ecntact with the carbon powder O, which is to be more or less compressed between the rubber disks, as will be now explained.

Lhe metallic cylinder fr is supported on an adjusting-rod, h, working in the screw-collar r. By this arrangement the cylinder l) and ts contents can he adjusted at pleasure in relation to the diaphragm K. The bottom of the cylinder l) has a chambered disk, upon the rim of which rests a disk of rubber, thus leaving an air-space, S, into which the rubber disk bulges more or less, as shown in Fig. 2.

A cap, T, closes the cylinder and presses more or less en the rubber disk, and through it upon the carbon powder; yet this cap has no contact with the small disk or bearing! on the pin L. By the above construction the carbon powder may be more or less compressed, and thus the compactness of the carbon and its consequent contact with the pin L may be increased or diminished at pleasure; and by the arrangement of the wires in connection with the telegraph-line and the metallic diaphragm K any movement ot' this diaphragm will deviate or vary the current according to the vibration. The metallic diaphragm K is thicker than those commonly used in similar instruments. The greater thickness ot' this metallic plate and the two rubber disks which embrace the carbon powder serve to break the backlash and thus prevent the ordinary rattling of the diaphragm when speaking or otherwise transmitting acoustic iniluence.

The rubber or elastic speaking-tube U is attached to the mouth-piece V by means ot' a screw-cap, lV, which bears against a projection or rounded shoulder of the mouth-piece, as seen in Fig. 3. In like manner this tube is also connected with the cap ofthe diaphragm K, Fig. 2.

Having described my invention,what I claim, and desire to secure by Letters Patent, is-

In a speaking-telephone or acoustic telegraph, the above-des ,ribed diaphragm or metallic plate K, having the pin L, provided with a bearing-disk, l, and having its point in 'contact with the pulverized carbon, in combination with the telegraph-wires and the acoustic cap K, substantially as set forth.

WEBSTER GLLETT.

Vitnesses:

GEo. F. GRAHAM, DANIEL BREED. 

